Decontamination of Dental Implant Surfaces in the Treatment of Peri-Implantits

Objectives: The chemical decontamination of infected implant surfaces is considered to be a critical step in the successful treatment of peri-implantitis. No standard cleaning protocol has yet been defined and current treatments often fail the requirement to efficiently remove microbial biofilm and inhibit reinfection. The objective of this study was to assess the antibacterial effect of H₂O₂-TiO₂ suspensions and compare it to conventional treatment with H₂O₂ and chlorhexidine.
Methods: S. epidermidis Xen 43 (biomluminescent) was used for biofilm formation on grit-blasted, acid etched titanium coins. Biofilms were grown for 8h and subsequently treated with 0.2% chlorhexidine, 3% H₂O₂ or a mixture of 3% H₂O₂ and 1g/l TiO2 nanoparticles. Treated samples were reincubated to allow regrowth of remaining viable bacteria. Luminescence was recorded during biofilm regrowth after decontamination (n=18). The decontamination outcome was further assessed by SEM and fluorescence microscopy after live/dead staining (n=3).
Results: The novel in vitro assay based on luminescence enabled the continuous monitoring of biofilm regrowth after the decontamination with different chemical agents. Bacterial regrowth was significantly delayed for H₂O₂-TiO₂ treated surfaces compared to conventional treatment with H₂O₂. No bacterial regrowth was observed for surfaces treated with chlorhexidine. Surfaces treated with H₂O₂ and H₂O₂-TiO₂ showed very few remaining clusters of bacteria while a distinctly higher bacterial load was found for chlorhexidine treated surface (SEM). Live/dead staining showed few viable bacteria on surfaces treated with H₂O₂ and H₂O₂-TiO₂ which contrasted with a uniform layer of dead bacteria for surfaces treated with CHX.
Conclusions: The antibacterial effect of H₂O₂ was enhanced by the addition of TiO₂ nanoparticles. In contrast to CHX, H₂O₂ and H₂O₂-TiO₂ could not prevent the regrowth of bacteria on decontaminated titanium surfaces. Future research is needed to evaluate the potentially cytotoxic effect of remaining TiO₂ particles.